DTC P2123 (Flash Code 121) Pedal Position Sensor 1 Circuit High Input (RZ4E-TC)

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Diagnostic system check-engine controls".

2. Accelerator pedal position sensor 1 signal voltage check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Start the engine.

4) Fully depress and release the accelerator pedal while observing the Accelerator Pedal Position (APP) Sensor 1 parameter on the scan tool. Does the scan tool display a value more than or equal to the specified value while the pedal is being depressed and released?

Value: 4.8 V

Yes

=>Go to Prioritized DTC and accelerator pedal position sensor 1 signal voltage check.

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(RZ4E-TC) intermittent conditions of engine".

3. Prioritized DTC and accelerator pedal position sensor 1 signal voltage check

1) Observe the DTC information with a scan tool for DTC P0641 being set at the same time.

Note

The diagnostic procedure varies depending on the set DTC.

2) Turn OFF the ignition switch.

3) Disconnect the accelerator pedal position sensor harness connector (C67).

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Turn ON the ignition switch.

5) Observe the Accelerator Pedal Position (APP) Sensor 1 parameter on the scan tool.

Value: 0.1 V

The reading is more than the specified value.

=>Go to Inspection for short to power supply in accelerator pedal position sensor 1 signal circuit.

The reading is less than or equal to the specified value and DTC P0641 is set.

Go to DTC P0641 diagnosis.

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P0641 (Flash Code 55) Sensor Reference Voltage 1 Circuit".

The reading is less than or equal to the specified value and DTC P0641 is not set.

=>Go to Accelerator pedal position sensor 1 low reference circuit inspection using test lamp.

4. Accelerator pedal position sensor 1 low reference circuit inspection using test lamp

1) Connect a test lamp between the accelerator pedal position sensor 1 low reference circuit (pin 5 of C67) and the battery power supply. Does the test lamp illuminate?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Accelerator pedal position sensor harness connector inspection.

=>Go to Inspection for open circuit in low reference circuit of accelerator pedal position sensor 1.

5. Inspection for short to power supply in accelerator pedal position sensor 1 signal circuit

1) Inspect the signal circuit between the ECM (pin 63 of C7) and accelerator pedal position sensor 1 (pin 6 of C67) for the following. Is the result normal?

Short to the battery power supply circuit or short to the ignition power supply circuit
Short to the 5 V reference circuit

Note

Accelerator pedal position sensor 1 may be damaged if the sensor signal circuit is shorted to the power supply.

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM replacement.

Repair the circuit as necessary.

=>Go to Repair verification.

6. Inspection for open circuit in low reference circuit of accelerator pedal position sensor 1

1) Inspect the low reference circuit between the ECM (pin 41 of C7) and accelerator pedal position sensor 1 (pin 5 of C67) for an open circuit or high resistance. Is the result normal?

Caution

Accelerator pedal position sensor 1 shares the low reference circuit with other sensors. A malfunction in the low reference circuit may set DTCs on sensors that share this circuit.

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM harness connector inspection.

Repair the circuit as necessary.

=>Go to Repair verification.

7. Accelerator pedal position sensor harness connector inspection

1) Inspect for poor connections at the accelerator pedal position sensor harness connector (pin 5 of C67). Is the connection status normal?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

Replace the accelerator pedal.

Refer to "1.Engine 1I.Speed Control Systems(RZ4E-TC) accelerator pedal removal".

Refer to "1.Engine 1I.Speed Control Systems(RZ4E-TC) accelerator pedal installation".

=>Go to Repair verification.

Repair the connections as necessary.

=>Go to Repair verification.

8. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pin 41 of C7). Is the connection status normal?

Refer to "RHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Engine Control (RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM replacement.

Repair the connections as necessary.

=>Go to Repair verification.

9. ECM replacement

Note

Perform programming after replacing the ECM.

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM setting".

Procedure completion

=>Go to Repair verification.

10. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Start the engine.

Value: 4.8 V

Yes

=>Go to Accelerator pedal position sensor 1 signal voltage check.

Observe the DTC information with a scan tool.